This invention relates to a diesel fueled coolant heater for vehicles powered by liquid cooled diesel burning engines.
When diesel powered vehicles such as construction equipment, truck tractors and the like are operated in cold climates, consideration must be given to the manner of starting a cold engine. Typically, when temperatures fall below freezing various means must be used in order to achieve a successful start and warm up of a diesel engine. As a consequence it is not uncommon for truck drivers and other vehicle operators to leave the vehicle engine running continuously during non-operating periods in order to avoid a cooling down of the engine and its associated coolant fluid, engine oil, etc. It is not uncommon, for example, to see trucks parked in cold climates with their engines running at idle speed in order to maintain engine heat while the driver is eating, sleeping or attending to other duties; or for construction equipment engines to be left running overnight.
In those instances where the driver of the vehicle utilizes the vehicle cab or driver compartment for sleeping purposes it is necessary to maintain the engine in a running condition during the period of sleep in order to provide heat for the driver.
It is well known that running a diesel engine for long periods of time at idle speed can be harmful to the components of the engine. Further, in view of increased fuel costs due to the present energy crisis there are severe cost disadvantages in running a vehicle engine at idle speed simply for the purpose of providing heat for the driver or for the purpose of avoiding engine cool down with the consequence that starting may be difficult.
Accordingly, this invention is directed to an engine coolant heater separately fired from the engine itself. The purpose of the heater is to provide auxiliary thermal energy for engine coolant to achieve two purposes, i.e., to maintain the engine block at a predetermined temperature during the time that the engine is shut off and to provide a source of thermal energy for the passenger compartment of the vehicle.
Auxiliary heaters for purposes of providing thermal energy for engine coolant fluids and to provide heating for the passenger compartment of a vehicle have been known for some time. There have been several drawbacks, however, with specific structures offered in the prior art.
Many of the auxiliary heaters previously offered to the trade burned gasoline, propane, or other fuel not compatible with a diesel engine. Consequently, the installation of such a heater in a diesel powered vehicle necessitated the addition of a separate fuel tank for the gasoline, propane, etc. Such additional fuel tank is not ordinarily provided by the manufacturer of the vehicle and, therefore, its installation as an additional tank may, in some cases, constitute a safety hazard. A further disadvantage in the installation of a separate fuel tank is the fact that a second fuel must be available at work sites or refueling stations. Accordingly, it may not be possible to provide for a fill up of the auxiliary heater tank at the same location as that providing diesel fuel.